Synthetic biology assemblies for sustainable space exploration

The work utilized synthetic biology to create sustainable food production processes by developing technology to efficiently convert inedible crop waste to supplemental high-protein food. The technology is based on modular enzyme complexes incorporating components from different organisms that have been shown to convert inaccessible cellulosic biomass like crop waste to soluble sugars more efficiently than enzymes without structural scaffolding. Long-duration crewed mission beyond low earth orbit will require significant supplies of food and closure of waste loops. Current crop growth systems produce approximately 50% inedible crop waste. Unique NASA-developed synthetic biology assemblies employ biomimicry to improve on naturally occurring enzymatic cellulosomes. These engineered enzyme complexes may be utlized to reduce crop waste by 50% and recover resources for food. Major constituents of crop waste include cellulose, hemicellulose and lignin. Our bioengineered assemblies would significantly improve the conversion of these constitutents to sugars by eliminating the need for chemical pretreatment and reducing the large amount of enzymes typically required. This will be accomplished by engineering synthetic cellulosomes for specifi ratios of cellulololytic enzymes that target these specific cellulosic components. The project completed a number of laboratory assays to compare enzymatic activity on a substrate of a select grouping of proteins attached to our synthetic cellulosome versus the activity unattached, in solution. Selection of groups is based upon reported combinations of enzymes that occur natually in the cellulosome. More »